Summary of "طريقة حل الاختبار النهائي"

Summary of "طريقة حل الاختبار النهائي" (How to Solve the Final Exam)

This video provides a detailed step-by-step guide on how to solve a final exam related to spatial data analysis using QGIS (referred to as QGS) and Power BI. The focus is on analyzing damage to buildings and schools within neighborhoods, classifying damage types, and calculating statistics such as percentages of damage. The methodology involves GIS data handling, spatial queries, attribute joins, and exporting results for further analysis.

Main Ideas and Concepts

Data Collection and Preparation:
- Collect spatial data layers including schools, administrative boundaries (neighborhoods), buildings, and damage layers.
- Load these layers into QGIS.
- Manage layer visibility and symbology to improve performance and clarity.
Data Analysis in QGIS:
- Understand damage classification in the "merging" (merger) column (e.g., total damage, severe damage, average damage, no damage).
- Use Selection by Attribute to select buildings classified as "total merge" (total damage).
- Use Selection by Location to relate damage points to buildings and schools.
- Identify discrepancies where damage points do not correspond to buildings.
Calculating Damage Percentages:
- Count total buildings and total damaged buildings.
- Calculate the percentage of damaged buildings using Excel or a calculator:
  - Formula: (Number of damaged buildings / Total buildings) * 100
- Example result: approximately 20.94% of buildings are totally damaged.
Damage Analysis for Schools:
- Select damaged schools by intersecting school points with damaged building layers.
- Address coordinate system issues causing displacement of layers (e.g., setting correct UTM zone or local coordinate system).
- Export selected damaged schools as a new layer.
- Use Join Attributes by Location to assign neighborhood names to schools.
- Handle cases where schools fall outside defined neighborhoods by labeling them as located in a "regional area."
Exporting and Reporting:
- Export spatial selections and joined attribute tables to Excel for reporting.
- Include X and Y coordinates in exported data for further use.
Power BI Integration:
- Export classified damage data (buildings and schools) with damage types.
- Import these layers into Power BI for visualization, such as heat maps of damage.
QGIS Cloud and GeoNode:
- Upload maps and data to QGIS Cloud or GeoNode for sharing and storytelling.
- Create projects that visualize damage classifications for buildings and schools.
Important Notes and Tips:
- The problem may seem complex but is solved by simple, logical spatial queries.
- Always check and correct coordinate reference systems to avoid layer displacement.
- When neighborhood data is missing for a school or building, manually assign a "regional area" label in the data table.
- This step is crucial and may appear in remedial or incomplete tests.

Detailed Methodology / Instructions

Load Data Layers:
- Open QGIS.
- Add vector layers: buildings, damage points, neighborhoods, schools.
- Turn off large layers temporarily to improve performance.
Set Symbology:
- Assign distinct colors to layers (e.g., orange for neighborhoods).
- Zoom to relevant areas to avoid loading excessive data.
Classify Damage:
- Open attribute tables.
- Identify damage types in the "merging" column.
- Select features where merging = "total merge" (use double quotes in queries).
Select Damaged Buildings:
- Use "Select by Expression" or "Select by Attribute" on buildings layer.
- Select buildings intersecting damage points classified as total damage.
Calculate Damage Percentage:
- Count total buildings and selected damaged buildings.
- Export counts to Excel.
- Calculate percentage = (damaged / total) * 100.
Analyze Damaged Schools:
- Select schools intersecting damaged buildings.
- Fix coordinate system issues if schools are displaced.
- Export selected damaged schools as a new layer.
Assign Neighborhood Names:
- Use "Join Attributes by Location" tool to join neighborhood names to schools.
- For schools outside neighborhoods, manually add "regional area" label in attribute table.
Export Data:
- Export final layers with damage classification and neighborhood info.
- Include coordinates for Power BI visualization.
Power BI Visualization:
- Import exported data.
- Create heat maps or other visuals to represent damage distribution.
Publish Maps:
- Upload projects to QGIS Cloud or GeoNode.
- Share maps and stories about damage analysis.